10 Chapter 10

*BOOM*

Under the pressure of Akaza's feet, the ground cracked as he vanished from his spot and reappeared in front of Kokushibo with his fist flying towards his face. Kokushibo used the back of his left hand and deflected the fist before slamming his own fist into Akaza's kidney.

Akaza tanked the hit with a big smile before sending a left hook towards Kokushibo's jaw which he dodged by moving his head back. Akaza saw this and headbutted Kokushibo and pushed himself away just before Kokushibo was about to kick him.

"Woah…" Kyoshi said as he watched from the sidelines. Their fight kicked up a lot of dirt and made strong winds with every shot they took. It was astonishing for Kyoshi to watch a sparring match between two uppermoons.

Akaza told him he was a martial artist like Habuki, but he practiced a different style. Kyoshi was interested in what style he practiced and seeing it now, he was very impressed by it. A style of martial arts that's aimed for the neck and the weapon of the opponent.

It also incorporated hits that targeted vitals for a quick death along with strong brute force hits to crush his opponents as brutally as possible. Kyoshi liked it so much that while he watched them he started physically copying the moves he saw Akaza doing.

Every kick, punch, and flip he did was copied by Kyoshi who was so immersed that he didn't notice they both stopped sparring and were watching him. Akaza was visibly impressed and intrigued. Kokushibo was staring at Kyoshi in a kinda dazed state. He started to see his younger brother in Kyoshi. The ability to see something once and perfectly copy it, just like his brother did when he took up the sword.

'Should I notify Master Muzan about this? I might as well.' Kokushibo thought as he looked towards Akaza.

"I'll be leaving." He said before vanishing.

Akaza walked over to Kyoshi and patted his shoulder. Akaza was a person that despised the weak and had an aim to become the strongest while fighting strong people.

Naturally seeing a kid copy his moves that he's been mastering all his time as a demon made him curious.

"Boy, have a sparring match with me." Akaza said.

"Ehh, but I'm not strong enough to fight with you. Would that really be sparring?" Kyoshi asked.

"You seemed to copy my moves well enough so let's go!!"

"…fine."

…

—Muzan's Estate—

Appearing in front of Muzan on a knee and with his head bowed, Kokushibo waited for Muzan to acknowledge his presence while he seemed to be writing things in his journal.

"Speak."

"Lord Muzan, I have a report about something I've seen with Kyoshi."

"Go on."

"While me and Akaza were sparring, Kyoshi was watching and when we stopped we noticed he was able to copy Akaza's moves perfectly even though this was his first time seeing them be performed."

"Hmm, I see. So his eyes can do that as well? You may leave." Muzan said.

Kokushibo then vanished from the estate leaving Muzan to his own thoughts.

So far he's found out a few things about Kyoshi. His body was using RC cells effectively before he was a demon, his eyes allow him to see on a cellular level, copy moves perfectly, and memorize anything at a mere glance.

'Interesting, but there's one thing I can't get over…' Muzan thought.

He looked into his microscope and saw Kyoshi's blood seemingly fighting Muzan's blood and eventually conquering it.

'I'm the progenitor of this damned race yet it seems my magic can't work on the boy.' He thought with frustration. He's had this case only once before and it wasn't that his magic didn't work, but she broke free of his control.

'Does she have something to do with this boy as well? A late offspring of sorts? No, he doesn't seem to hold any resemblance to her and the boy still seems to hold his human memories.'

Muzan was wrecking all of his brains for a solution to why his curse wouldn't work on Kyoshi. The only way for this to be possible is for Kyoshi to not be a demon, but Muzan himself gave the boy blood so that wasn't possible either.

Breaking free from the curse? He didn't even know that a curse was on him. He doesn't have much knowledge of talismans and spells, so that's out.

'Forget about that for now. As long as he believes we're his family, anything he does should be fine. It's not like I can't kill him if he gets out of line.' Muzan thought as he went back to testing different plants and mixtures looking for something that can be used to fight the sun.

…

As time went on Kyoshi met all of the 12 Kizuki and got to know them all pretty well. Over time they also seemed to get used to his random visits and pop ins, especially Daki and the ladies at the red light district.

They used him as a makeup doll, a model, and more importantly they even had him bring in customers, but immediately stopped when Daki got warned by Muzan that Kyoshi wasn't going to be used for them.

After Kyoshi told Akaza that he learned martial arts from Habuki, Akaza started to do "joint training" with them. Although they were no match for the Upper rank 3, they were gradually getting stronger.

The more people and demon slayers they ate the stronger they got. Although Akaza told them as long as they're his pupils they are banned from eating women. Even if they're demon slayers.

That was rather peculiar, but none of them complained. After all, it's a small price to pay for the tutelage of a demon like Akaza.

Other than martial arts training with Habuki and Akaza, Along with sword training with Kokushibo and the usual visits to Daki and Keiko, Kyoshi had a rather interesting relationship with the other upper rank demons.

They kinda weirded him out, but not in a bad way. Well all other than Doma. He went against Akaza's rule of not eating women thinking they would live a better and more fulfilling life in his stomach.

One thing nobody saw coming was that he spent quite a bit of time with Nakime. Not even the upper ranks talked to her and she seemed like Kokushibo most of the time. Cold and unapproachable.

That was until Kyoshi kept bothering her about teaching him to play different instruments. She didn't just play the biwa, but she was a bit of a prodigy herself when it comes to instruments and unsurprisingly Kyoshi was as well.

Over the course of 3 years Kyoshi learned to play the biwa, the piano, the shakuhachi, the koto, the shamisen and lastly the piano. His achievements weren't looked over nor did they end there. Alongside Muzan he kept getting better and better at Chemistry and Biology. Even without what he called his kakugan activated he can tell you exactly where the organs are placed and their functions in the body.

He could draw out the entire body and make his own anatomy charts. This along with his mastery in poisons was something Muzan was slightly proud of. It was like he was an instructor teaching a younger, more interested version of himself.

He even went so far as to buy him a white lab coat like he was a real scientist. Of course he never stopped seeing Habuki and Keiko who obviously liked each other but kept it between themselves.

Kyoshi often hunted with them since more and more people hiked up the mountain for things like fire wood when winter came around. They killed many people and grew stronger so they wouldn't end up dying by those demon slayers.

As time went on they both secured the ranks of Lower moon 1 and 3. Habuki with 1 and Keiko with 3.

…

—Sound Hashira Mansion—

In the front yard of Tengen, The Sound Hashira's mansion was 14 year old Seikichi Hachizume and 4 demon slayer trainees sparring. Seikichi had his blindfold on and was barehanded while the trainees had their swords.

They slashed at him, tried using forms, and even had amazing team work yet it seemed like Seikichi knew about everything going on around him. He dodged, blocked and counted everything they threw at him. It was like he had eyes in the back of his head.

His movements were swift, strong and clean. He didn't even break a sweat nor did he use his sword. After getting their ass beat for about an hour and a half, they were let off to do their daily training since that was just a warmup.

Seikichi went over to the water well and sat on the edge of the wall as he drank some. Seikichi grew out his brown hair into a ponytail and his bangs started to grow over his blindfold.

"I assume you're done with your warmup!!" Tengen said as he jumped down from his roof, did 4 front flips in the air, and landed gracefully on his feet as he basked in all his flamboyant glory.

"…Yes and for once could you act like a normal person?" Seikichi asked as he sighed heavily. These two were basically the complete opposite of each other. One was energetic and flashy while the other was plain and simple.

"My student, we aren't normal people!! Use demon slayers have to show everyone just how amazing we are and to do so in style. YOU Seikichi, are the underwhelming one!!" Tengen said while pointing at Seikichi who just stared at him.

"Yeah, sure." Seikichi said before standing up.

"Where are you going? I don't think you have any missions today." Tengen said.

"I'm going to see my best friend's sister. It'll be her 5th birthday tomorrow." He answered before flashing away.

"Time sure flies. To think it's been four years since that boy got here and he's gotten this far. Heheheh HIS PROGRESS IS INDEED FLAMBOYANT!!" Tengen yelled before he too vanished.

He had a mission to complete in the east and wanted to put on the best show he could.

…

—Butterfly Mansion—

"Where's Hinā?" Seikichi asked Shinobu in a rather stale voice.

"Sei-kun, that's rather cold of you. Even after everything you did to me last night." Shinobu responded.

Her adoptive sister froze up behind her after having a vague memory of hearing all the groaning and moaning from her room last night.

'Weirdo's…' Aoi thought as she left the kitchen area.

"Where's Hinā?" Seikichi asked again.

"If you're still stressed I can do it again. Even though you didn't really satisfy me."

"Woman, it was a massage!!" Seikichi said, slamming his hand on the counter in both frustration and embarrassment. Shinobu laughed, seeing his face slightly red even though he had the blindfold covered almost everywhere other than his mouth.

"She's in the backyard with Kanao." She answered with a small smile.

Seikichi walked out of the kitchen and outside before walking around the house and to the backyard. He saw Hinā playing around with the three little helpers of the mansion.

Sitting on the porch watching them was Kanao. She was a year older than Seikichi, and stood at 5'1(156cm). She had big, gentle eyes that were a lilac color with thick eyelashes. She had thin black hair that was tied into a ponytail by a pink and green butterfly ornament given to her by Kanae.

Seikichi nodded towards her, knowing she doesn't talk much and went towards Hinā.

"Seikichi!!"Hinā shouted when she saw him walking towards her. He went down on one knee and hugged her. For Hinā, Seikichi was her older brother. She knew him for as far back as she could remember and he was always with her whenever she called.

As for Seikichi, he thought of her as his adoptive sister. His best friend died and so did his family, but she was alive and so was he, so he decided to just own up and raise her since he thought Kyoshi would've wanted that.

He also made it clear that he didn't want her in any part of demon slaying whatsoever and obviously nobody protested. She mainly stayed at the Butterfly Mansion, being taken care of by Shinobu and the rest while Seikichi was training till every drop of energy in his body was depleted.

He was a prodigy like Kanao. He already learned Total Concentration breathing; Constant, all forms of Sound Breathing,Third World View, and Shinobi Tactics.

Although he wasn't the strongest because he hadn't mastered them nor was he as experienced as them in the field, everyone knew he would be a force to be reckoned with in the near future. His dedication was crazy scary and the mercilessness he had for demons made him an even better Demon Slayer.

Fit to be a future Hashira.

…

As everyone was enjoying themselves with Kyoshi and the demons getting closer while still on the search for the Blue Spider Lily. Seikichi and the Demon Slayers preparing for Hinā's birthday party.

A boy that had his family slaughtered by Muzan Kibutsuji had just received his sword and has officially become a demon slayer.

The boy who'd been trained by the former Water Hashira was now ready to set off and exact his revenge on the demon that killed his family and turned his sister into a demon.

Two years of training prepared him for this exact task. The Kisanagi Crow just gave him his mission and his master Sakonji was just sending him off.

"Stay safe out there, Tanjiro." He said.

"Of course." Tanjiro said as he ran down the dirt path with his sleeping sister in a box on his back.